Is it possible to turn off the "bass amplifier" feature on them? If so, turn it off and they should be ok. If not, it may effect the entrainment waves on the tracks, but that would depend exactly what "bass amplifier" is actually doing.

The recommendation is to use headphones that do not alter the sound in any way, and just play it as it's been supplied by the track.

I have some cheapo sony's that fit in the ear that seem ok but I also used over the ear airplane headphones with noise reduction but I think its better to leave the noise reduction off but would like confirmation on that. They are PlaneQuiet NC-6 active noise reduction